Franklin, who is competing in seven events at her first Olympics, also has a bronze and one more race to add to her haul in the 4x100 medley relay Saturday.
Unlike the men, the American women haven't won the medley relay since 2000. Australia took gold at the last two Olympics and led the way into the final as top qualifier, looking to bring a bit of joy to the battered team from Down Under, normally a powerhouse of the pool but limited to just one swimming gold so far in London.
Also on the schedule for the final night of swimming: the long (men's 1,500 freestyle) and short (women's 50 free) of it.
Sun Yang of China goes into the 1,500 with the top qualifying time, followed by defending Olympic champion Ous Mellouli of Tunisia, who also will compete in the 10-kilometer open water event at Hyde Park next week. Connor Jaeger was the lone American to make the final.
Ranomi Kromowidjojo of the Netherlands led the semifinals of the 50 free, gunning for another gold to add to her victory in the 100 free. Jessica Hardy of the U.S. also qualified.
In Phelps' victory, le Clos tied with Russia's Evgeny Korotyshkin for the silver in 51.44. Milorad Cavic, who lost to Phelps by one-hundreth of a second in Beijing, tied for fourth in 51.81, not even close in their final meeting.
"I cannot be compared to Michael Phelps," said Cavic, who also plans to retire after the London Games. "I'm a one-trick pony."
Ledecky seemingly came out of nowhere to make the U.S. team, and nearly took out a world record in her first Olympics. She was ahead of Rebecca Adlington's record pace (8:14.10) from the Beijing Olympics until right at the end, finally tiring just a bit for a time of 8:14.63.
She settled for crushing Janet Evans' American mark of 8:16.22, set in Tokyo on Aug. 20, 1989.
"I figured I was going pretty fast," the teenager said.
Ledecky has plenty of time to go faster, becoming the second-youngest American swimmer to claim an individual gold medal — 75 days older than Beth Botsford was when she won the 100 backstroke at the 1996 Atlanta Games.
Mireia Belmonte Garcia of Spain was far behind for silver in 8:18.76, while Britain's defending Olympic champion held on to take bronze at 8:20.32. Adlington burst into tears on the medal stand as the crowd of 17,000 chanted "Becky! Becky! Becky!"
She had no chance of catching Ledecky.
"That is nothing to be ashamed of," Adlington said. "I was disappointed with the time. I was fast all year. I know it. I don't know why I wasn't. Maybe it was the expectation, the environment, maybe it got to me a little bit."
France won its fourth gold at the pool, building on its best showing ever and denying an American sweep Friday. Florent Manaudou — younger brother of 2004 gold medalist Laure Manaudou — shocked defending Olympic champion and world record-holder Cesar Cielo of Brazil in the 50 freestyle.
Manaudou touched in 21.34 and pounded the water out in Lane 7, then got a big hug from his sister as soon as he climbed from the pool. Cullen Jones of the United States took silver in 21.54, while Cielo was left with bronze in 21.59. Anthony Ervin, the 2000 Olympic champion who came back from an eight-year retirement, finished fifth after getting off to a poor start.
"Being here is my own form of redemption," Ervin said. "What's next? I'm going to have a nice dinner with my friends and family."
What's next for Phelps?
One more race.
Follow Paul Newberry on Twitter at www.twitter.com/pnewberry1963
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